From middle school through college, students are taught that each plant or animal cell has a nucleus a simple, round sphere containing the organism's genetic blueprint.
In an accidental discovery, however, researchers at North Carolina State University have found it's not that simple, after all.
The researchers discovered that, far from being uniformly round spheres, plant cell nuclei can be deeply grooved and furrowed. They appear somewhat like human brains when viewed three-dimensionally.
The team, led by Dr. Nina Strmgren Allen, NC State professor of botany, and Dr. David Collings, a former postdoctoral fellow in her laboratory, has published its findings in the scientific journal The Plant Cell.
Using green fluorescent protein (GFP) to highlight the structure of tobacco and onion skin cells under a confocal microscope, the researchers noticed deep groves on the surface of, and tunnels through, the cell nuclei. GFP is a new tool used by biologists to label cell organelles and molecules so that they can be imaged clearly at high resolution with a light microscope.
Although the scientists aren't certain about the reason for the grooves and tunnels, they note that the structures greatly increase the nucleus' surface area relative to the surrounding, jellylike cell cytoplasm.
That, they say, may assist in the communication of chemical messages and molecules between the nucleus and cell parts contained in the cytoplasm, because greater surface area may allow more molecules and chemical signals to pass quickly back and forth.
The nucleus contains the cell's DNA, the genetic instruction manual that tells a cell how to operate and replicate itself. Chemical signals, molecules and ribosomes specialized cell particles that synthesize proteins continually move in and out of the cell nucleus.
The researchers also found that the tunnels and folds in the cell nucleus contain cytoplasm and bundles of actin filaments, strings of protei
Contact: Dr. Nina Strmgren Allen
North Carolina State University